JP5927984B2 - Image processing apparatus and image processing program - Google Patents

Description

  The present invention relates to image processing including enlargement processing.

  The image processing apparatus may generate enlarged image data by executing enlargement processing for enlarging the size of the original image using original image data representing the original image. For example, if the enlargement process is executed when printing, a relatively large print image can be printed even if the original image is relatively small.

JP-A-8-258255 JP 2003-319182 A

  However, when the enlargement process is performed, the appearance of the edge may be impaired in the enlarged image. For example, in an enlarged image obtained by enlarging the original image twice in the horizontal direction, the step for one pixel in the horizontal direction in the original image becomes a step for two pixels, so that the edge including the step has a rattling. There was a case where it stood out.

  The main advantage of the present invention is to improve the appearance of the edge in the enlarged image after the enlargement process.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples.

  Application Example 1 Original image data representing an original image including a first type pixel and a second type pixel, and a color difference between the color of the first type pixel and the color of the second type pixel is An acquisition unit that acquires the original image data that is equal to or greater than a specific reference value, and enlargement image data that represents an enlarged image obtained by enlarging the original image in a first direction by executing enlargement processing on the original image data An enlargement processing unit that generates the enlargement image when the original image includes a specific pattern composed of the first type of pixels and the second type of pixels. A pixel group selecting unit that selects a pixel group extending in a second direction intersecting the first direction, wherein the pixel group in the enlarged image corresponds to a specific pixel in the original image A specific pixel, and a pixel located in the second direction of the corresponding specific pixel. The specific pixel in the original image is a pixel corresponding to the specific first type pixel constituting the specific pattern, and the number of pixels constituting the pixel group in the enlarged image is a first number It is a number according to a continuous number and a second continuous number, and the first continuous number is a number in which the first pattern continues from the specific pixel toward the second direction in the original image. The second continuous number is a number in which the second pattern continues from the specific pixel toward the opposite direction of the second direction in the original image, and in the enlarged image An image processing apparatus comprising: a setting unit that sets the pixels constituting the pixel group of the second group of pixels.

  According to the above configuration, the pixel group of the enlarged image including the pixel corresponding to the specific pixel which is the first type pixel constituting the specific pattern of the original image is selected, and the selected pixel group is set as the second type pixel. Set. The number of pixels constituting the pixel group is a number corresponding to the first continuous number and the second continuous number. As a result, it is possible to improve the appearance of the edge of the enlarged image corresponding to the specific pattern in consideration of the image around the specific pattern of the original image.

Application Example 2 In the image processing apparatus according to Application Example 1, the first pattern includes a first central pixel that is the first type of pixel and the first central pixel. A first adjacent pixel that is the first type of pixel adjacent in the first direction and a second type of pixel that is adjacent to the first central pixel in the opposite direction of the first direction. The second pattern is adjacent to the second central pixel, which is the second type of pixel, in the first direction with respect to the second central pixel. And a third adjacent pixel that is the first type of pixel, a position of the first central pixel in the first direction, and a position of the second central pixel in the first direction. Is the same as the position of the specific pixel in the original image in the first direction.
According to the above configuration, the number of pixels constituting the pixel group can be determined appropriately.

Application Example 3 In the image processing apparatus according to Application Example 1 or Application Example 2, the first pattern is a first partial pattern that is a part of the specific pattern, and the second pattern is An image processing apparatus that is a second partial pattern that is a part of the specific pattern and is different from the first partial pattern.
According to the above configuration, it is possible to appropriately select an edge whose appearance is to be improved and improve the appearance of the edge.

Application Example 4 In the image processing device according to any one of Application Example 1 to Application Example 3, the specific pattern includes a first partial pattern adjacent to the specific pixel in the second direction; A second partial pattern adjacent to the specific pixel in a direction opposite to the second direction, and the first partial pattern includes a central pixel adjacent to the specific pixel in the second direction A first peripheral pixel that is the first type of pixel adjacent to the central pixel in the first direction, and the second type of pixel adjacent to the central pixel in a direction opposite to the first direction. A second peripheral pixel that is a pixel of the second type, and the second partial pattern is a second type of pixel that is adjacent to the specific pixel in a direction opposite to the second direction. The first pixel with respect to the peripheral pixel and the third peripheral pixel; A fourth peripheral pixel is the first type of pixels adjacent to the direction, a pattern including the image processing apparatus.
According to the above configuration, it is possible to appropriately select an edge whose appearance is to be improved and improve the appearance of the edge.

Application Example 5 In the image processing device according to any one of Application Example 1 to Application Example 4, in the case where the enlargement processing unit has the first continuous number larger than the second continuous number, The number of pixels constituting the pixel group is determined using the second continuous number, and when the first continuous number is smaller than the second continuous number, the number of pixels constituting the pixel group is determined. An image processing apparatus comprising: a determination unit that determines a number using the first continuous number.
According to the above configuration, the number of pixels constituting the pixel group can be appropriately determined.

Application Example 6 In the image processing device according to any one of Application Examples 1 to 5, the enlargement processing unit sequentially selects a target pixel from among a plurality of pixels constituting the original image. A target pixel selection unit, and the enlargement processing unit executes any one of a plurality of processes including a first process and a second process each time the target pixel is selected, thereby the enlarged image Data is generated, and the first process is a process executed when the target pixel includes the specific pixel, wherein the pixel group is selected by the pixel group selection unit, and the pixel group is set by the setting unit. The second process is a process executed when the target pixel does not include the specific pixel, and the pixel group is selected by the pixel group selection unit. Selection and the pixel group by the setting unit Setting the pixels constituting a process that does not include the image processing apparatus.
According to the above configuration, enlarged image data that can improve the appearance of the edge can be easily created.

Application Example 7 In the image processing apparatus according to any one of Application Example 1 to Application Example 6, the enlargement processing unit performs the enlargement process on the original image without distortion so as to reduce distortion. The enlarged image data representing the enlarged image is generated, and the image processing device is a device for a print execution unit that prints a dot image, and the image processing device is further generated by the enlargement processing unit. Dot data representing a distorted dot image by executing a halftone process for generating dot data representing a dot formation state for each pixel on the enlarged image data representing the enlarged image having a distorted distortion A halftone processing unit that generates the image and a process different from the enlargement process on the distorted dot data, and the distortion dot image is expanded at least in the second direction without distortion Comprising a dot image enlargement unit that generates a strain-free dot data representing the distortion dot image, the image processing apparatus.
According to the above configuration, the amount of halftone processing for printing an undistorted dot image can be reduced, and the appearance of the edge can be improved in the printed undistorted dot image.

Application Example 8 In the image processing device according to Application Example 7, the undistorted dot image includes a plurality of sets of the same row, and the set of the same row configures the undistorted dot image. Among the plurality of rows along the first direction, the set includes two or more rows that are adjacent to each other and in which the dot formation state of each constituent pixel is the same, and the undistorted dot data is the same An image processing apparatus including compressed data representing a set of rows, wherein the compressed data includes representative row data representing one representative row and data indicating that the representative row data is repeated.
According to the above configuration, the data amount of undistorted dot data can be reduced.

  Application Example 9 In the image processing apparatus according to any one of Application Examples 1 to 8, the enlargement processing unit includes a detection unit that detects the specific pattern in the original image, and the enlargement processing unit An image processing apparatus that executes the selection of the pixel group by the pixel group selection unit and the setting of the pixels constituting the pixel group by the setting unit for the detected specific pattern.

  [Application Example 10] The image processing apparatus according to any one of Application Examples 1 to 8, wherein the enlargement processing unit displays a corresponding specific pattern corresponding to the specific pattern of the original image in the enlarged image. A detection unit for detecting, the enlargement processing unit, for the detected correspondence specific pattern, the selection of the pixel group by the pixel group selection unit, the setting of the pixels constituting the pixel group by the setting unit, An image processing apparatus that executes

  The present invention can be realized in various forms, for example, in the form of a method for realizing the function of the device, a computer program for realizing the function of the device, a recording medium on which the computer program is recorded, and the like. Can be realized.

1 is a block diagram of a computing device 100 and a printing device 200 according to an embodiment. The flowchart of an image process. The conceptual diagram explaining image processing. The flowchart of a compression process. The figure which shows the compression dot data 300 notionally. The figure which shows dither matrix DM1. The figure explaining the screen angle of dither matrix DM1. The figure explaining the screen angle which appears in the undistorted dot image GD2. The flowchart of a horizontal direction expansion process (FIG. 2: S600). The figure explaining the specific pattern and the pattern for a count in the horizontal direction expansion process of an Example. The flowchart of an edge complementation process. The figure explaining an edge complementation process. The figure which shows the example of arrangement | positioning of the complementary pixel in an enlarged image. The figure which shows the example of arrangement | positioning of the complementary pixel in an enlarged image. The figure which shows the edge of the printing image of an Example, and the edge of the printing image of a comparative example. The figure explaining the specific pattern and the pattern for a count in a vertical direction expansion process. The flowchart of the horizontal direction expansion process in a modification. The figure explaining the specific pattern and the pattern for counting in the horizontal direction expansion process of a modification.

A. Example:
A-1: Configuration of Computing Device 100 and Printing Device 200 An embodiment of the present invention will be described based on examples. FIG. 1 is a block diagram of a computing device 100 as an image processing device and a printing device 200 according to an embodiment.

  The computing device 100 is a computer (for example, a personal computer) that is communicably connected to the printing device 200. The computing device 100 includes a CPU 110, an internal storage device 120 such as a ROM and a RAM, an external storage device 130 such as a hard disk, an operation unit 170 such as a keyboard and a mouse, a display unit 180 such as a liquid crystal display, and an external device ( For example, a communication unit 190 including an interface for communication with the printing apparatus 200) is provided.

  The external storage device 130 stores a driver program 132 as an image processing program of the present embodiment and image data 134 created by an application program (not shown).

  The CPU 110 implements the function of the printer driver M10 by executing the driver program 132. The printer driver M10 includes an image data acquisition unit M12, an enlargement processing unit M14, a halftone processing unit M16, a dot image enlargement unit M18, and a compression unit M19, and executes image processing (described later) of this embodiment. To do. The enlargement processing unit M14 includes a target pixel selection unit M141, a pattern detection unit M142, a continuation number determination unit M143, a pixel group selection unit M144, and a pixel data setting unit M145.

  The printing apparatus 200 communicates with the integrated circuit 210, the printer engine 250, an operation unit 270 such as various buttons and a touch panel, a display unit 280 such as a liquid crystal panel, and an external device (for example, the computing device 100). And a communication unit 290 including the interface.

  The integrated circuit 210 is, for example, an ASIC (Application Specific Integrated Circuit), and includes a control circuit 212, a volatile memory 214 such as a DRAM, and a nonvolatile memory 216 such as a mask ROM or an EEPROM. The volatile memory 214 provides a buffer area used by the control circuit 212. The nonvolatile memory 216 stores control data, programs, and the like that are referred to by the control circuit 212. The control circuit 212 functions as an apparatus control unit M20 that controls the entire printing apparatus 200. Note that all or part of the volatile memory 214 and the nonvolatile memory 216 may be provided outside the integrated circuit 210.

  The printer engine 250 is a mechanism unit that performs printing in accordance with the control of the device control unit M20 (integrated circuit 210) and the print data supplied from the device control unit M20. The printer engine 250 realizes a function as a monochrome laser printer that prints a dot image on a printing medium using black toner as a printing material, for example. In other words, the printer engine 250 exposes the photosensitive member using a laser, a developing step for attaching toner to the electrostatic latent image formed on the photosensitive member by exposure, and the developed toner image. A transfer process for transferring from the photoreceptor to the print medium and a fixing process for fixing the transferred toner image on the print medium are realized. The entire apparatus control unit M20 and the printer engine 250 are examples of a print execution unit.

  The driver program 132 that realizes the function of the printer driver M10 and the program that realizes the function of the apparatus control unit M20 may be provided in a form stored in a computer-readable recording medium.

A-2: Image processing of printer driver M10:
FIG. 2 is a flowchart of image processing executed by the printer driver M10 of the computing device 100. This image processing is processing for generating print data to be supplied to the printing apparatus 200 using the image data 134. For example, the printer driver M10 starts image processing in response to a user's print instruction.

  In step S100, the image data acquisition unit M12 of the printer driver M10 acquires image data to be processed (target image data). The target image data is, for example, the above-described image data 134 (FIG. 1), and is acquired from the application program that created the image data 134. The target image data has a different data format for each application program that created the image data.

  In step S200, the image data acquisition unit M12 executes rasterization processing for converting the target image data into bitmap data (RGB image data) composed of RGB pixel data. The RGB pixel data includes gradation values (for example, 256 gradations) of RGB color components.

  In step S300, the image data acquisition unit M12 converts the RGB image data into bitmap data (monochrome image data) composed of monochrome pixel data representing the density of the black (K) component (monochrome conversion processing). In the present embodiment, the monochrome pixel data is a gradation value in the range of 0 to 255, the gradation value “0” represents white, the gradation value “255” represents black, and the intermediate gradation value represents a gradation value. The higher the logarithm, the higher the density of gray. Specifically, the image data acquisition unit M12 calculates a luminance value Y of RGB pixel data, for example. The image data acquisition unit M12 converts the luminance value Y into single-color pixel data using a lookup table.

  In step S400, the image data acquisition unit M12 determines whether or not the monochrome image represented by the generated monochrome image data is a vertically long image (portrait), that is, the ratio of the number of pixels in the horizontal direction to the number of pixels in the vertical direction. It is determined whether or not the image is smaller than 1. If the image data acquisition unit M12 determines that the monochrome image is not a portrait image, that is, a landscape image (landscape) (step S400: NO), the image data acquisition unit M12 performs a rotation process that rotates the monochrome image by 90 degrees. Thus, monochrome image data representing a vertically long monochrome image is generated (step S500). If the image data acquisition unit M12 determines that the single-color image is a vertically long image (step S400: YES), the process proceeds to step S600.

  FIG. 3 is a conceptual diagram illustrating image processing. FIG. 3A shows a monochromatic image PG1 represented by monochromatic image data (a monochromatic image PG1 after the rotation process when the 90-degree rotation process is performed). The size (number of pixels) of the monochromatic image PG1 of this embodiment is 3407 pixels long × 2380 pixels wide. The pixel number ratio S of the monochrome image PG1 is about 0.70. The pixel number ratio S is the ratio of the number of pixels in the horizontal direction to the number of pixels in the vertical direction.

  In step S600, the enlargement processing unit M14 of the printer driver M10 doubles the size of the monochrome image PG1 in the horizontal direction with respect to the monochrome image data (increases the number of pixels in the horizontal direction by 2). Execute the enlargement process. By the horizontal enlargement process, enlarged monochrome image data representing the enlarged monochrome image PG2 is generated. FIG. 3B shows an enlarged monochromatic image PG2. Specific processing contents of the horizontal enlargement processing will be described later.

  The number of pixels in the horizontal direction of the enlarged monochrome image PG2 is twice the number of pixels in the horizontal direction of the monochrome image PG1, and is 4760 pixels in the example of FIG. The number of pixels in the vertical direction of the enlarged monochrome image PG2 is 3407 pixels, which is the same as the number of pixels in the vertical direction of the monochrome image PG1. That is, the pixel number ratio S2 of the enlarged monochrome image PG2 is twice the pixel number ratio S of the monochrome image PG1, and is about 1.40 in the example of FIG. Here, as shown in FIGS. 3A and 3B, the enlarged single-color image PG2 is a distorted image obtained by distorting the single-color image PG1 without distortion. Hereinafter, the monochromatic image PG1 is also referred to as an undistorted image PG1, and the enlarged monochromatic image PG2 is also referred to as a distorted image PG2. Further, the monochrome image data representing the undistorted image PG1 is also referred to as undistorted image data, and the enlarged monochrome image data representing the strained image PG2 is also referred to as strain image data.

  In step S700, the halftone processing unit M16 of the printer driver M10 performs halftone processing on the acquired distorted image data. The halftone process is a process for generating dot data representing a dot formation state for each pixel using a dither matrix DM1 (FIG. 5: described later). Specifically, each pixel data constituting the dot data is either “1” indicating that the corresponding pixel forms a dot, or “0” indicating that the corresponding pixel does not form a dot. It is binary data that takes the value of. By the halftone process of this step, distorted dot data representing a distorted dot image GD1 corresponding to the distorted image PG2 (FIG. 3B) is generated. FIG. 3C shows an example of the distorted dot image GD1. The number of pixels in the vertical direction and the number of pixels in the horizontal direction of the distorted dot image GD1 are the same as the number of pixels in the vertical direction and the number of pixels in the horizontal direction of the distorted image PG2. Therefore, the pixel number ratio of the distorted dot image GD1 is also the same as the pixel number ratio S2 of the distorted image PG2.

  In step S800, the dot image enlargement unit M18 of the printer driver M10 performs dot image enlargement processing on the distorted dot data to generate undistorted dot data representing the undistorted dot image GD2 without distortion. FIG. 3D shows an example of the undistorted dot image GD2.

  Specifically, the dot image enlargement unit M18 inserts copy data of the nth row data between the nth row data constituting the distorted dot data and the (n + 1) th row data. Generates undistorted dot data. Accordingly, in the undistorted dot data, the odd-numbered row data and the even-numbered row data next to the odd-numbered row data are the same data. Therefore, as shown in FIGS. 3C and 3D, each pixel data representing each pixel PX2 in the (2n-1) th row of the undistorted dot image GD2 represented by the undistorted dot data and each of the 2nth row Each pixel data representing each pixel PX2 is the same data (each pixel data representing each pixel PX2 in the nth row of the distorted dot image GD1). Each pixel data representing each pixel PX2 in the (2n + 1) th row of the undistorted dot image GD2 represented by the undistorted dot data and each pixel data representing each pixel PX2 in the (2n + 2) th row are the same data ( Each pixel data representing each pixel PX2 in the (n + 1) th row of the distorted dot image GD1.

  The number of pixels in the vertical direction of the undistorted dot image GD2 is twice the number of pixels in the vertical direction of the strained dot image GD1, the undistorted image PG1, and the distorted image PG2 (for example, 6814 pixels). The number of pixels in the horizontal direction of the undistorted dot image GD2 is the same as the number of pixels in the horizontal direction of the distorted dot image GD1 and the distorted image PG2, and is twice the number of pixels in the horizontal direction of the undistorted image PG1 (for example, 4760 pixels). Therefore, the pixel number ratio of the undistorted dot image GD2 is the same as the pixel number ratio S of the undistorted image PG1, and is ½ of the pixel number ratio S2 of the distorted image PG2 and the distorted dot image GD1.

  Here, as in the set of the (2n-1) th row and the 2nth row of the undistorted dot image GD2, the plurality of rows constituting the undistorted dot image are adjacent to each other, and A set of two or more rows having the same dot formation state (pixel value of pixel data constituting the dot data) is also referred to as a set of the same row. In addition, a set of row data representing a set of the same row included in the undistorted dot data is also referred to as a set of the same row data. When the number of pixels (number of rows) in the vertical direction of the undistorted dot image GD2 is N, the undistorted dot image GD2 includes a set of (N / 2) identical rows.

  In step S900, the compression unit M19 of the printer driver M10 generates a compressed dot data 300 by executing a compression process for compressing the undistorted dot data. FIG. 4 is a flowchart of the compression process. FIG. 5 is a diagram conceptually showing the compressed dot data 300.

  In step S902, the compression unit M19 sequentially processes the rows constituting the undistorted dot image GD2 represented by the undistorted dot data to be processed (specifically, from the top in FIG. 3D). Choose as. In step S904, the compression unit M19 determines whether the row data of the processing target row (processing target row data) is the same as the previous processing target row data. In this example, when the odd-numbered row is a processing target row, the processing target row data and the previous processing target row data are not the same. On the other hand, when the even-numbered row is a processing target row, the processing target row data is the same as the previous processing target row data.

  When the compression unit M19 determines that the processing target row data is not the same as the previous processing target row data (step S904: NO), the compression unit M19 generates reference flag data representing a reference flag of “OFF” (step S906). In step S908, the compression unit M19 generates compressed row data and data amount data representing the data amount of the compressed row data. The compression unit M19 compresses the processing target row data by run length compression to generate compressed row data.

  When the compression unit M19 determines that the processing target row data is the same as the previous processing target row data (step S904: YES), the compression unit M19 generates reference flag data representing a reference flag of “ON” (step S910).

  In step S912, the compression unit M19 determines whether or not all the rows constituting the undistorted dot image GD2 represented by the undistorted dot data to be processed are selected as the processing target rows. If all the rows have not been selected as processing target rows (step S912: NO), the compression unit M19 returns to step S902, sets the unselected rows as new processing selection rows, and performs steps S904 to S910. Repeat the process. When all the rows have been selected as processing target rows (step S912: YES), the compression unit M19 ends the compression processing.

  As shown in FIG. 5, the compressed dot data 300 generated by the compression process includes data representing each row of the undistorted dot image GD2. The data representing the odd-numbered rows (for example, data in the first row and the third row in FIG. 5) includes “OFF” reference flag data 310A, data amount data 320, and compressed row data 330. Data representing even lines (for example, data in the second and fourth lines in FIG. 5) includes reference flag data 310B of “ON”. The “OFF” reference flag data 310 </ b> A is a flag indicating that the data amount data 320 and the compressed row data 330 having the data amount represented by the data amount data 320 follow thereafter. The “ON” reference flag data 310B is data indicating that the line represented by the immediately preceding compressed line data 330 is repeated. As described above, when the rows represented by the same data are repeated, information indicating that the row data representing the second and subsequent rows among the repeated rows is referred to the immediately preceding row data ("ON"). The dot data is compressed by replacing it with the reference flag data 310B). This compression processing is also referred to as “pre-reference compression processing”.

  As understood from the above description, the set of the data 310A, 320, 330 representing the odd rows and the data 310B representing the even rows next to the odd rows is the compressed data representing the set of the same rows described above. This is compressed data obtained by compressing the set of the same row data described above. The compressed data representing a set of the same row includes representative row data representing one representative row (in this example, data 310A, 320, 330 representing odd rows) and data representing that the representative row data is repeated (in this example) Then, it can be said that the data includes a set with data 310B) representing an even-numbered row.

  In step S1000 of FIG. 2, the printer driver M10 adds various printer control codes and data identification codes to the generated compressed dot data 300, and the apparatus control unit M20 (FIG. 1) of the printing apparatus 200 interprets them. Generate possible print data. In step S1100, the printer driver M10 transmits the generated print data to the printing apparatus 200, and ends the process.

  The apparatus control unit M20 (integrated circuit 210) of the printing apparatus 200 that has received the print data stores the print data in the volatile memory 214. The apparatus control unit M20 prints the undistorted dot image GD2 by sequentially supplying the compressed dot data 300 included in the print data to the printer engine 250 while restoring it by a predetermined amount (for example, by a specific number of rows). .

A-3. Dither matrix DM1:
FIG. 6 shows the dither matrix DM1. The dither matrix DM1 is configured by arranging 升 PM1 corresponding to each pixel (FIG. 3C) of the distorted dot image GD1 in 8 rows × 16 columns (128 in total). The dither matrix DM1 includes 2 vertical × 4 horizontal = 8 sub-matrixes CE1, and each sub-matrix includes 16 rows PM1 of 4 rows × 4 columns. A threshold TH1 is defined for each bag PM1. The numbers shown inside each bag PM1 in FIG. 6 indicate the threshold value TH1 set for each bag PM1. In this example, the 128 threshold values TH1 are set so as to be distributed substantially evenly over the entire range (for example, 0 to 255) that the input gradation value can take. As a result, the distorted dot image GD1 represented by the distorted dot data generated using the dither matrix DM1 can express 128 gradations in the range of 8 pixels vertically × 16 pixels horizontally.

  FIG. 7 is a diagram for explaining the screen angle of the dither matrix DM1. In the schematic diagram of FIG. 7, among the 升 PM1 of the dither matrix DM1, a region corresponding to 升 PM1 having a threshold TH1 of 112 or less is hatched, and a region corresponding to 升 PM1 having a threshold TH1 greater than 112 is white. FIG. FIG. 7 can also be said to show a partially distorted dot image PGD1 that appears in the distorted dot image GD1 represented by the distorted dot data generated using the dither matrix DM1. That is, the partially distorted dot image PGD1 corresponds to dot data obtained by performing halftone processing on an image area having a constant density composed of single-color pixel data having a gradation value of 122.

  As can be seen from the partially distorted dot image PGD1 shown in FIG. 7, in the distorted dot image GD1, a set of dots DT1 corresponding to the sub-matrix CE1 in the dither matrix DM1 appears. As can be seen from the solid line DL1 shown in FIG. 7, a plurality of dot lines formed by connecting a plurality of dots DT1 appear in the distorted dot image GD1. The angle of this dot line represents the screen angle of the dither matrix DM1. Generally, the screen angle φ is represented counterclockwise by the angle from the 3 o'clock direction (right direction in FIG. 6) to the dot line. In this example, the screen angle φ is about 26.56 degrees. A dot line is a line formed by a plurality of dots along the direction of the screen angle.

  FIG. 8 is a diagram for explaining a screen angle appearing in the undistorted dot image GD2 to be printed. FIG. 8 shows a region of the undistorted dot image GD2 (also referred to as a partially undistorted dot image PGD2) corresponding to the partially distorted dot image PGD1 shown in FIG.

  As can be seen from the partial undistorted dot image PGD2 shown in FIG. 8, the set of dots DT2 appearing in the undistorted dot image GD2 is twice the corresponding set of dots DT1 (FIG. 7) appearing in the distorted dot image GD1 in the vertical direction. The shape is enlarged. As can be seen from the solid line DL2 shown in FIG. 8, the undistorted dot image GD2 has a plurality of dot lines formed by connecting a plurality of dots. The angle of this dot line, that is, the screen angle appearing in the undistorted dot image GD2 to be printed is defined as θ. In this example, the screen angle θ is about 45 degrees.

  Incidentally, the tangent (tan φ) of the screen angle φ (screen angle appearing in the distorted dot image GD1) of the dither matrix DM1 is TL1 / YL1. Here, TL1 is the horizontal period of the plurality of dot lines of the distorted dot image GD1 (in the example of FIG. 7, a length corresponding to 4 pixels (4 升)). YL1 is a horizontal period of the plurality of dot lines of the distorted dot image GD1 (in the example of FIG. 7, a length corresponding to 8 pixels (8 cm)). Then, the tangent (tan θ) of the screen angle θ appearing in the undistorted dot image GD2 is TL2 / YL2. Here, TL2 is a horizontal period of the plurality of dot lines of the undistorted dot image GD2 (in the example of FIG. 8, a length corresponding to 8 pixels (8 cm)). YL2 is a period in the horizontal direction of a plurality of dot lines of the undistorted dot image GD2 (in the example of FIG. 8, a length corresponding to 8 pixels (8 cm)). Since TL2 = 2 × TL1 and YL1 = YL2, tan φ = (tan θ) / 2. Therefore, it can be said that the screen angle φ of the dither matrix DM1 is set to about arctan ((tan θ) / 2).

  A line interval L between a plurality of dot lines of the distorted dot image GD1 is represented by cosφ × TL1. Further, the line interval D of the plurality of dot lines of the undistorted dot image GD2 is represented by cos θ × TL2. Therefore, it can be said that the line interval L of the plurality of dot lines of the distorted dot image GD1 is set to L = (1/2) × D × cos φ / cos θ. Here, as described above, φ = arctan ((tan θ) / 2). In the present embodiment, the line interval L of the distorted dot image GD1 is approximately 3.16 pixels and the line interval D of the undistorted dot image GD2 is approximately equal to about a dot image pixel corresponding to one 升 PM1 of the dither matrix DM1. 5.66 pixels.

  The screen angle θ appearing in the undistorted dot image GD2 to be printed and the number of lines (unit: Lpi (line per inch)) determined based on the line spacing D of a plurality of dot lines of the undistorted dot image GD2 are known screens. It can be easily recognized by measuring the printed undistorted dot image GD2 using a gauge.

A-4. Horizontal enlargement processing:
FIG. 9 is a flowchart of the horizontal enlargement process (FIG. 2: S600). As described above, the horizontal enlargement process is a process executed on undistorted image data representing the undistorted image PG1. As a result of the horizontal enlargement process, distorted image data representing the distorted image PG2 in which the size of the undistorted image PG1 in the horizontal direction is doubled (the number of pixels in the horizontal direction is doubled) is generated. In the description of the horizontal processing, the undistorted image PG1 is also referred to as an original image, and the undistorted image data is also referred to as original image data. The distorted image PG2 is also referred to as an enlarged image, and the distorted image data is also referred to as enlarged image data. In this horizontal enlargement process, not only the horizontal size of the original image is doubled, but also a complementary pixel is added to the enlarged image in order to improve the appearance of the edge of the enlarged image ( Edge complement processing).

  In step S605, the target pixel selection unit M141 of the enlargement processing unit M14 sequentially selects the target pixels SP to be processed one by one from the pixels constituting the original image (undistorted image PG1). Specifically, in this processing, the processing target is set downward from the top row (pixel row in the left-right direction) of the undistorted image PG1 shown in FIG. In the same row, processing is sequentially performed from the leftmost pixel toward the right.

  In step S610, the enlargement processing unit M14 determines whether the target pixel SP is a white pixel using the pixel value (pixel data) of the target pixel SP. As described above, the pixel value (monochromatic pixel data) of the pixels constituting the undistorted image PGA represents an achromatic color having a higher density (closer to black) as the number of gradations increases. Here, the white pixel is, for example, a pixel having a pixel value of 0 or a value relatively close to 0, specifically, a pixel having a pixel value equal to or less than a white pixel determination reference value (for example, 5). It is. That is, a white pixel is a pixel whose pixel value is any one of 0-5, for example. Note that a black pixel described later is, for example, a pixel having a pixel value having a pixel value of 255 or relatively close to 255, specifically, a pixel value equal to or greater than a black pixel determination reference value (for example, 250). Pixel. That is, a black pixel is a pixel whose pixel value is any one of 250-255, for example. A pixel excluding a black pixel and a white pixel (for example, a pixel having a pixel value of 6 or more and 249 or less) is also referred to as a gray pixel.

  If it is determined that the target pixel SP is not a white pixel (step S610: NO), the enlargement processing unit M14 determines whether or not the pixel (corresponding target pixel) TP in the enlarged image corresponding to the target pixel SP is not set. To do. If the coordinates of the target pixel SP of the original image are (Xa, Ya), the coordinates of the corresponding target pixel TP of the enlarged image are (2Xa, Ya) and (2Xa + 1, Ya). The coordinates of the original image (undistorted image PG1 (FIG. 3A)) and the coordinate of the enlarged image (distorted image PG2 (FIG. 3B)) are both set to the origin (0, 0) at the upper left of the image. The coordinates (unit is pixel) are used with the right direction as the positive direction of the X axis and the downward direction as the positive direction of the Y axis.

  If the enlargement processing unit M14 determines that the corresponding target pixel TP is not set (set) (step S615: NO), the process proceeds to step S635. When the enlargement processing unit M14 determines that the corresponding target pixel TP has not been set (step S615: YES), the pixel values of the two corresponding target pixels TP that have not been set are the same as the pixel values of the target pixel SP, respectively. (Pixel data of the corresponding target pixel TP is generated).

  When the enlargement processing unit M14 determines that the target pixel SP is a white pixel in step S610 described above (step S610: YES), the pattern detection unit M142 of the enlargement processing unit M14 determines that the target pixel SP is the same as the target pixel SP. With respect to the peripheral pixels, it is determined whether or not any of four types of specific patterns 1 to 4 to be described later is formed (step S625).

  FIG. 10 is a diagram for explaining the specific pattern and the counting pattern in the horizontal enlargement process of the present embodiment. As shown in FIG. 10, the four types of specific patterns 1 to 4 are each composed of a total of nine pixels of 3 × 3.

  The specific pattern 1 includes a central part pattern MP1 composed of three pixels arranged in the horizontal direction, an upper part pattern UP1 that is adjacent to the upper part of the central part pattern MP1, and a lower part that is adjacent to the lower part of the central part pattern MP1. And a partial pattern BP1.

  The central partial pattern MP1 is a white pixel, a central pixel that is a white pixel, a right adjacent pixel that is a white pixel adjacent to the central pixel in the right direction, and a black pixel that is adjacent to the central pixel in the left direction. Adjacent pixels. Similar to the central partial pattern MP1, the upper partial pattern UP1 is a central pixel that is a white pixel, a right adjacent pixel that is a white pixel adjacent to the central pixel in the right direction, and a left direction relative to the central pixel. And a left adjacent pixel which is an adjacent black pixel. The lower part pattern BP1 includes a central pixel that is a black pixel and a right adjacent pixel that is a white pixel adjacent to the central pixel in the right direction. In the lower partial pattern BP1, the pixel adjacent to the center pixel in the left direction (FIG. 10: the pixel with the letters “any”) is any pixel (white pixel, black pixel, or gray pixel). )

  A central pixel (white pixel marked with a cross in FIG. 10) in the central partial pattern MP1 is also referred to as a central pixel of the specific pattern 1. The pattern detection unit M142 determines whether the target pixel SP and its peripheral pixels correspond to the specific pattern with the target pixel SP as the central pixel. In FIG. 10, the cross-hatched pixel represents a black pixel, and the non-hatched pixel and the cross-hatched pixel (center pixel) represent a white pixel.

  The specific patterns 2, 3, and 4 are respectively the center partial patterns MP 2, MP 3, and MP 4 including the central pixel, and the upper partial patterns UP 2, UP 3, and UP 4 that are adjacent in the upper direction of the central partial patterns MP 2, MP 3, and MP 4 The lower partial patterns BP2, BP3, and BP4 that are adjacent in the lower direction of the partial patterns MP2, MP3, and MP4 are included. As shown in FIG. 10, the specific pattern 2 is a pattern obtained by inverting the specific pattern 1 up and down, the specific pattern 3 is a pattern obtained by inverting the specific pattern 1 left and right, and the specific pattern 4 The pattern is inverted up and down.

  When the target pixel SP and its surrounding pixels do not form any of the specific patterns 1 to 4 (step S625: NO), the pixel data setting unit M145 of the enlargement processing unit M14 performs the processing of steps S615 and 620 described above. I do. That is, if the corresponding target pixel TP corresponding to the target pixel SP is not set, the pixel data setting unit M145 sets the pixel value of the corresponding target pixel TP to the same value as the pixel value of the target pixel SP. The process proceeds to S635.

  When the target pixel SP and its surrounding pixels form any one of the specific patterns 1 to 4 (step S625: YES), the enlargement processing unit M14 performs an edge complement process (step S630).

  FIG. 11 is a flowchart of edge complement processing. In step S6305, the continuous number determination unit M143 sets a counting pattern for counting the continuous number according to a specific pattern formed by the target pixel SP and its peripheral pixels. FIG. 10 shows the counting patterns corresponding to the specific patterns 1 to 4, respectively. The counting pattern includes a first pattern LCP for counting the first continuous number CL and a second pattern UCP for counting the second continuous number CU.

  The first pattern LCP is the same pattern as the partial pattern adjacent to the central pixel in the count direction CD1 (FIG. 10: described later) with respect to the center pixel among the three partial patterns included in the corresponding specific pattern. It is. The second pattern UCP is the same pattern as the partial pattern adjacent to the central pixel in the count direction CD2 (FIG. 10: described later) of the second consecutive number CU among the three partial patterns included in the corresponding specific pattern. It is. For example, as shown in FIG. 10, the first pattern LCP1 corresponding to the specific pattern 1 is the same as the upper pattern UP1 of the specific pattern 1, and the second pattern UCP1 corresponding to the specific pattern 1 is the specific pattern 1 is the same as the lower part pattern BP1. The first pattern LCP2 corresponding to the specific pattern 2 is the same as the lower part pattern BP2 of the specific pattern 2, and the second pattern UCP2 corresponding to the specific pattern 2 is the same as the upper part pattern UP2 of the specific pattern 2 is there.

  More specifically, the first pattern LCP1 corresponding to the specific pattern 1 includes a central pixel (white pixel) located in a vertical pixel row where the central pixel of the specific pattern 1 is located, and the central pixel. A right adjacent pixel (white pixel) adjacent in the right direction and a left adjacent pixel (black pixel) adjacent in the left direction with respect to the center pixel are included. That is, the horizontal position of the center pixel (white pixel) of the first pattern LCP1 is the same as the horizontal position of the center pixel of the specific pattern 1. The second pattern UCP1 corresponding to the specific pattern 1 includes a central pixel (black pixel) located in the vertical pixel row where the central pixel of the specific pattern 1 is located, and a right adjacent to the central pixel in the right direction. Adjacent pixels (white pixels). That is, the horizontal position of the central pixel (black pixel) of the second pattern LCP2 is the same as the horizontal position of the central pixel of the specific pattern 1. In the second pattern UCP1, a pixel adjacent to the center pixel in the left direction (FIG. 10: a pixel on which “any” is written) is an arbitrary pixel (a white pixel, a black pixel, or a gray pixel). Either). Here, in this example, the number of pixels of the first pattern LCP1 (3 pixels) and the number of pixels of the second pattern LCP2 (3 pixels) are the same, but they may be different. For example, the second pattern LCP2 may be composed of two pixels excluding the pixels on which the characters “any” are written.

  In step S6310, the continuous number determining unit M143 counts the first continuous number CL and the second continuous number CU using the counting pattern (first pattern LCP and second pattern UCP). The first continuous number CL is a number in which the first pattern LCP continues from the target pixel SP in the count direction CD1. The second continuous number CU is a number in which the second pattern UCP continues from the target pixel SP toward the count direction CD2. A combination of the count direction CD1 and the count direction CD2 is determined for each of four types of specific patterns. The count direction CD1 and the count direction CD2 are opposite to each other. As shown in FIG. 10, in the case of the specific pattern 1, the count direction CD1 is upward and the count direction CD2 is downward. In the case of the specific pattern 2, the count direction CD1 is downward, and the count direction CD2 is upward.

  FIG. 12 is a diagram for explaining edge complement processing. As shown in FIG. 12A, an example will be described in which a specific pattern 2 is formed in an area AR of 3 vertical pixels × 3 horizontal pixels centering on the target pixel SP. In this case, the first continuous number CL = 3 and the second continuous number CU = 4.

  In step S6315, the continuous number determination unit M143 determines whether or not at least one of the first continuous number CL and the second continuous number CU is one. When at least one of the first continuous number CL and the second continuous number CU is 1 (step S6315: YES), the continuous number determining unit M143 sets the complementary number SC to 1 To decide. If both the first continuous number CL and the second continuous number CU are not 1 (step S6315: NO), the continuous number determining unit M143 determines that the first continuous number CL is the second continuous number CU. It is determined whether it is larger (step S6325).

  When the continuous number determination unit M143 determines that the first continuous number CL is larger than the second continuous number CU (step S6325: YES), the complementary number SC is set to (second continuous number CU-1). ) (Step S6330). When the continuous number determination unit M143 determines that the first continuous number CL is equal to or smaller than the second continuous number CU (step S6325: NO), the complementary number SC is set to (first continuous number CL / 2 (however, if it is not divisible by 2, it is rounded off to be an integer value)) (step S6335).

  In the example shown in FIG. 12A, the first continuous number CL <the second continuous number CU. In this case, since the first continuous number CL / 2 = 3/2 = 1.5, it is rounded off to determine the complement number SC = 2.

  When the complement number SC is determined, the enlargement processing unit M14 sets the pixel value of the pixel including the complement pixel (step S6340). Specifically, the pixel group selection unit M144 of the enlargement processing unit M14 selects the pixel group SCP to be set in the enlarged image. FIG. 12B illustrates an example of the pixel group SCP. The pixel group SCP includes a set of corresponding target pixels TP (coordinates (2Xa, Ya), (2Xa + 1, Ya)) corresponding to the target pixel SP (coordinates (Xa, Ya)). Further, when the complement number SC is 2 or more, the pixel group SCP includes one corresponding target pixel TP ((SC-1) pixels continuous in the complement direction SD from the coordinates (2Xa, Ya), and the other Corresponding pixel TP (coordinate (2Xa + 1, Ya) to (SC-1) pixels continuous in the complementary direction SD. In other words, the pixel group SCP includes a set of two pixels arranged in the horizontal direction as SC. 2 × SC pixels are included, and the complementary direction SD is determined for each of four types of specific patterns as shown in Fig. 10. The complementary direction SD is a count of the first continuous number CL. In the example of Fig. 12B, the complement number SC = 2, and the pixel group SCP has coordinates (2Xa, Ya), (2Xa + 1, Ya) pixel set and coordinates 2xa, Ya-1), including four pixels including a set of pixels of the (2Xa + 1, Ya-1).

  The pixel data setting unit M145 sets each set of two pixels arranged in the horizontal direction included in the selected pixel group SCP in the complementary pattern SDP. The complementary pattern SDP is determined for each of the four types of specific patterns (FIG. 10: SDP1 to SDP4). As a result, in the enlarged image shown in FIG. 12, among the pixels included in the pixel group SCP, the pixel group adjacent to the black pixel in the horizontal direction is set as a black pixel. In the enlarged image, among the pixels included in the pixel group SCP, a pixel group in which white pixels are adjacent in the horizontal direction is set as a white pixel. In the case of the specific patterns 1 and 2, the pixel group in which the black pixels are adjacent to each other in the horizontal direction is a pixel group in the pixel column having the X coordinate of 2Xa in the pixel group SCP. Is a pixel group of a pixel column whose X coordinate is (2Xa + 1) in the pixel group SCP. Here, for the pixel set as the black pixel, for example, the pixel value may be set to 255, or the pixel value may be set to a black pixel in the vicinity of the target pixel SP of the original image (for example, in the right direction or The pixel value of a black pixel adjacent in the left direction may be set to the same value. In addition, for a pixel set as a white pixel, for example, the pixel value may be set to 0, or the pixel value may be set to the same value as the pixel value of the target pixel SP of the original image.

  Returning to FIG. 9, the description will be continued. In step S635, the enlargement processing unit M14 determines whether all the pixels of the original image have been selected as the target pixel SP. When the enlargement processing unit M14 determines that there is an unselected pixel (step S635: NO), the process returns to step S605, selects the unselected pixel as a new target pixel SP, and performs the above-described steps S610 to S630. Repeat the process. If the enlargement processing unit M14 determines that all the pixels have been selected (step S635: YES), the enlargement processing unit M14 ends the lateral enlargement processing.

  An enlarged image (distorted image PG2 (FIG. 3B)) generated by the horizontal enlargement process is an image obtained by adding complementary pixels to a simple enlarged image. Here, in the simple enlarged image, the same pixel column as the m-th pixel column is arranged between the m-th pixel column along the vertical direction constituting the original image and the (m + 1) -th pixel column. It is an image. That is, in the simple enlarged image, the odd-numbered pixel column and the even-numbered pixel column next to the pixel column are the same. The pixel group constituting the complementary pixel (the pixel set as the black pixel in step S6340 (FIG. 11) described above) is a specific pixel (specific pattern) among the nine pixels forming the specific patterns 1 to 4 in the original image. Is a pixel of the supplement number SC including the pixel (corresponding specific pixel) of the enlarged image corresponding to the white pixel located at the center of the pixel and extending in the vertical direction.

  In the example of the enlarged image shown in FIG. 12B, the cross-hatched pixel indicates a black pixel constituting the simple enlarged image, and the single-hatched pixel indicates a black pixel that is a complementary pixel. The same applies to an example of an enlarged image shown in FIG.

  FIG. 12C shows a print image (undistorted dot image GD2) corresponding to the enlarged image (distorted image PG2) shown in FIG. In FIG. 12C, cross-hatched pixels indicate dot formation pixels (pixels with a pixel value “1”) corresponding to black pixels that form a simple enlarged image in the enlarged image. The single-hatched pixel indicates a dot formation pixel corresponding to a complementary pixel in the enlarged image. As described with reference to FIG. 2, the print image is an image obtained by enlarging the distorted image PG2 twice in the vertical direction. Therefore, in the print image, the number of dot formation pixels SCD corresponding to the complementary pixels is enlarged. This is twice the number of complementary pixels in the image (FIG. 12B).

  According to the present embodiment described above, the pixel group selection unit M144 is a specific pixel (in the present embodiment, each specific pattern that is a white pixel constituting any one of the specific patterns 1 to 4 (FIG. 10) in the original image. The pixel group SCP of the enlarged image including the corresponding specific pixel corresponding to (the pixel located at the center of the nine pixels forming the pixel) is selected (FIG. 12). The pixel data setting unit M145 sets one pixel group of the two pixel groups SCP as a black pixel, that is, arranges a complementary pixel in a region corresponding to the pixel group SCP. The number of pixels set as black pixels (complement number SC) is a number corresponding to the first continuous number CL and the second continuous number CU. As a result, it is possible to improve the appearance of the edge of the enlarged image corresponding to the specific pattern in consideration of the arrangement of the pixels in the upward direction and the pixels in the downward direction when viewed from the specific pixels of the specific pattern of the original image.

  More specifically, for example, the specific pattern 1 is a pattern including the upper part pattern UP1, the center part pattern MP1, and the lower part pattern BP1 shown in FIG. That is, the specific pattern 1 is a pattern in which the shape formed by the black pixels is L-shaped (a shape having a level difference of one pixel in the horizontal direction). The same applies to the other specific patterns 2 to 3.

  13 and 14 are diagrams illustrating an example of the arrangement of complementary pixels in an enlarged image. 13A to 13F and FIGS. 14A and 14B, the left side shows an example of a part of the original image, and the right side shows an enlarged image corresponding to a part of the left original image. A part is shown. Moreover, the broken line in the enlarged images shown in FIGS. 13 and 14 roughly indicates the direction of the edge formed by the white pixel and the black pixel.

  As can be seen from these figures, the level difference of one pixel in the horizontal direction in the original image is a level difference of two pixels in the horizontal direction in the simple enlarged image. Therefore, in the simple enlarged image, the shakiness of the edge in the oblique direction is larger than that in the original image. As a result, shakiness of the edge in the oblique direction is easily noticeable in the undistorted dot image GD2 that is finally printed using the simple enlarged image.

  In the present embodiment, as described above, an L-shaped specific pattern is detected and set as a complementary pixel arrangement target. Therefore, an edge that should be improved in appearance is appropriately selected to improve the appearance of the edge. Can do. For example, in the example shown in FIGS. 13A to 13E, complementary pixels are arranged, but in the example shown in FIG. 13F, no complementary pixels are arranged. As a result, by arranging the complementary pixels, it is possible to prevent the complementary pixels from being arranged at a place where the entire shape of the edge (for example, see the broken line in FIG. 13F) may be damaged. Can do. FIGS. 13A to 13E and FIG. 14A show examples of complement target locations corresponding to the specific pattern 2, and FIG. 14B shows complement target locations corresponding to the specific pattern 2 ( An example is shown in which the upper side) and the complement target portion (lower side) corresponding to the specific pattern 1 are close to each other.

  Furthermore, the continuous number determination unit M143 counts the first continuous number CL using the first patterns LCP1 to LCP4 that are the same patterns as the partial patterns UP1, BP2, UP3, and BP4 of the specific patterns 1 to 4. The continuous number determination unit M143 uses the second patterns UCP1 to LCP4, which are the same patterns as the partial patterns BP1, UP2, BP3, and UP4 of the specific patterns 1 to 4, to count the second continuous number CU. As a result, it is possible to appropriately count the first continuous number CL and the second continuous number CU for determining the complement number SC.

  Furthermore, when the first continuous number CL is greater than the second continuous number CU, the continuous number determining unit M143 determines the complement number SC using the second continuous number CU (specifically, SC = CU−1 (FIG. 11: S6330).

  For example, FIG. 13A shows an example in which there is one complementation target portion where the first continuous number CL = 7 and the second continuous number CU = 4, and FIG. An example is shown in which there are two complementation target portions where the continuous number CL = 7 and the second continuous number CU = 4. In this example, by using the second continuous number CU, the complement number SC is set to an appropriate number (3), so that the entire shape of the edge extending in the direction indicated by the broken line is maintained and the edge is smoothed. Has been. Further, in the example of FIG. 14B, the complement number SC is set to an appropriate number (upper and lower three), so that the pixel indicated by the symbol VP in FIG. 13 is not set as a black pixel. That is, the upper complementary pixel and the lower complementary pixel are prevented from being connected. As a result, the edge can be smoothed without the step to be expressed being lost by the complementary pixels.

  Furthermore, when the first continuous number CL is equal to or less than the second continuous number CU, the continuous number determining unit M143 determines the complement number SC using the first continuous number CL (specifically) Specifically, SC = CL / 2 (FIG. 11: S6335).

  For example, FIG. 13B illustrates an example of a complement target portion where the first continuous number CL = 4 and the second continuous number CU = 4, and FIG. 13D illustrates the first continuous number CL = 4. 2 shows an example in which the complement target portion where the second continuous number CU = 4 is set. In this example, by using the first continuous number CL, the complement number SC is set to an appropriate number (FIG. 13B: 2, FIG. 13D: 1), and the direction indicated by the broken line The edges are smoothed while maintaining the overall shape of the edges that extend to.

  Furthermore, the continuous number determination unit M143 determines the complement number SC as 1 when at least one of the first continuous number CL and the second continuous number CU is 1 (FIG. 11: S6320). ).

  For example, FIG. 13C illustrates an example of a complement target portion where the first continuous number CL = 1 and the second continuous number CU = 1, and FIG. 13E illustrates the first continuous number CL = FIG. 14A shows an example of a complement target location where 1 and the second continuous number CU = 4, and FIG. 14A shows a complement target location where the first continuous number CL = 4 and the second continuous number CU = 1. An example is shown. In these examples, by setting the complement number SC to an appropriate number (one), the edges are smoothed while maintaining the overall shape of the edges extending in the direction indicated by the broken line.

  As described above, as a result of determining the complement number SC by appropriately using the first continuous number CL and the second continuous number CU, in the enlarged image, while maintaining the entire shape of the edge to be reproduced, Shaking can be suppressed. Therefore, in the final printed image (undistorted dot image GD2), it is possible to suppress the rattling of the edge while maintaining the entire shape of the edge of the original image.

  FIG. 15 is a diagram illustrating an edge of the print image of the present embodiment and an edge of the print image of the comparative example. FIG. 15A shows an example in which the target image data acquired in step S100 (FIG. 2) is a portrait. FIG. 15B shows an example in which the target image data acquired in step S100 (FIG. 2) is a landscape. 15A and 15B, the right side shows the case where the image processing of the present embodiment is performed, that is, the case where the complementary pixel is added, and the left side shows the case where the simple enlarged image is used, that is, This shows a case where no complementary pixel is added.

  In both FIGS. 15A and 15B, the print image of this embodiment on the right side is the entire edge formed by white pixels and black pixels as compared to the print image using the left side simple enlarged image. It can be seen that the rattling of the edge is suppressed even though the shape has not changed. In the printed image of this example, it can be seen that the rattling of the edges is remarkably suppressed particularly at the edges (for example, portions indicated by reference numerals E1 to E6) extending in the oblique direction.

  Further, the enlargement processing unit M14 of the present embodiment sequentially selects the target pixel SP from the plurality of pixels constituting the original image (FIG. 9: S605, S635), and every time the target pixel SP is selected, By executing one of the first process including the edge complement process (FIG. 9: Step S630) and the second process not including the edge complement process (for example, FIG. 9: Steps S615 and S620), the enlarged image is displayed. Data is being generated. The first process is executed when the target pixel SP includes a specific pixel (a central pixel of a pixel group that forms a specific pattern). The second process is executed when the target pixel SP does not include the specific pixel. As a result, it is possible to easily create an enlarged image (undistorted image PG1) to which complementary pixels are added.

  Further, according to the present embodiment, the halftone processing unit M16 uses the dither matrix, and the distorted dot data representing the distorted dot image GD1 in which the pixel number ratio S2 is twice the pixel number ratio S of the undistorted image PG1. (FIG. 2: S700). Then, the dot image enlargement unit M18 performs dot image enlargement processing on the distorted dot data to generate undistorted dot data representing the undistorted dot image GD2 (FIG. 2: S800). As a result, the halftone processing unit M16 only needs to generate distorted dot data representing the distorted dot image GD1 smaller than the undistorted dot image GD2, so that the processing amount of the halftone process can be reduced.

  In the above-described embodiment, the compression unit M19 compresses the undistorted dot data representing the undistorted dot image GD2 including the set of the same row using the pre-reference compression process (FIG. 4). The amount of data can be reduced. Accordingly, the amount of print data transmitted to the printing apparatus 200 can be reduced. As a result, the memory capacity required for the printing apparatus 200 (for example, the capacity of the volatile memory 214) can be reduced.

  Further, the screen angle appearing in the printed image, that is, the screen angle appearing in the undistorted dot image GD2 (partial undistorted dot image PGD2 (FIG. 8)) in this embodiment affects the image quality. For example, in human visual characteristics, it is known that the resolution for vertical and horizontal stripe patterns is high and the resolution for diagonal stripe patterns is low. For this reason, the stripe pattern in the vertical direction and the horizontal direction is easily noticeable, and the stripe pattern in the oblique direction is not easily noticeable. In consideration of such human visual characteristics, in monochrome printing, the screen angle appearing in a printed image is generally set to 45 degrees. According to the above configuration, the screen angle φ of the dither matrix DM1 is φ = arctan ((() so that the screen angle appearing in the undistorted dot image GD2 (partial undistorted dot image PGD2 (FIG. 8)) becomes the target value θ. tan θ) / 2). Specifically, the screen angle φ of the dither matrix DM1 is about 26.56 degrees so that the screen angle θ appearing in the undistorted dot image GD2 (partial undistorted dot image PGD2 (FIG. 8)) is about 45 degrees. Is set to As a result, the screen angle appearing in the print image, that is, the undistorted dot image GD2, can be optimized and the image quality of the print image can be improved.

  The number of lines in the printed image (unit is line per inch), that is, the number of lines in the undistorted dot image GD2 (partial undistorted dot image PGD2 (FIG. 8)) in this embodiment affects the image quality. . For example, when the number of lines is small, the size of a set of adjacent dots (corresponding to the submatrix CE1 (FIG. 6)) increases, so that the stability of the toner is improved and problems such as banding occur. It becomes difficult. On the other hand, when the number of lines is small, the image becomes rough and the edge shakiness increases. An appropriate number of lines is determined in consideration of such advantages and disadvantages. The number of lines in the undistorted dot image GD2 (partial undistorted dot image PGD2 (FIG. 8)) is determined by the line interval D described above. According to the above configuration, the dither matrix DM1 has the distorted dot image GD1 (partially distorted dot image so that the line interval appearing in the undistorted dot image GD2 (partial distorted dot image PGD2 (FIG. 8)) becomes the target value D. PGD1: The line interval L shown in FIG. 7) is set to be approximately (1/2) × D × cos φ / cos θ, where φ = arctan ((tan θ) / 2). As a result, the image quality of the print image can be improved by optimizing the line interval D appearing in the print image, that is, the undistorted dot image GD2, and the number of lines determined by the line interval D.

  As can be understood from the above description, either one of the upward direction and the downward direction in this embodiment is an example of the first direction, and either the right direction or the left direction intersects the first direction. It is an example of the second direction. Further, the upper part patterns UP1 and UP3 of the specific patterns 1 and 3 in this embodiment are examples of the first part pattern, and the lower part patterns BP1 and BP3 of the specific patterns 1 and 3 in this embodiment are the second part patterns. It is an example of a pattern. In addition, the lower part patterns BP2 and BP4 of the specific patterns 2 and 4 in the present embodiment are examples of the first partial pattern, and the upper part patterns UP2 and UP4 of the specific patterns 2 and 4 in the present embodiment are the second part patterns. It is an example of a pattern.

B. Variations:
(1) In the embodiment, the enlargement processing unit M14 enlarges the original image (undistorted image PG1) and generates the enlarged image (distorted image PG2) as a process of enlarging the original image in the horizontal direction. Although the process (FIG. 2: step S600) is executed, a vertical enlargement process for enlarging the original image in the vertical direction may be executed. For example, when the target image data acquired in step S100 (FIG. 2) is a landscape, the enlargement processing unit M14 does not perform the 90-degree rotation process (FIG. 2: S500), and instead of the horizontal enlargement process. Further, the vertical enlargement process may be executed. In this case, the 90 degree rotation process may be performed on the enlarged image data representing the enlarged image (distorted image) generated by the vertical enlargement process before the halftone process (FIG. 2: S700). preferable.

FIG. 16 is a diagram illustrating a specific pattern and a count pattern in the vertical enlargement process. The vertical enlargement process is basically the same as the horizontal enlargement process (FIGS. 9 and 11) in the embodiment, except for the following points.
1) In the vertical enlargement process, if the coordinates of the target pixel SP of the original image are (Xa, Ya), the coordinates of the corresponding target pixel TP of the enlarged image are (Xa, 2Ya) and (Xa, 2Ya + 1).
2) As shown in FIG. 16, the four types of specific patterns 1 to 4 of the vertical direction enlargement process rotate the four types of specific patterns 1 to 4 (FIG. 10) of the horizontal direction enlargement process by 90 degrees (FIG. 16). In this example, the pattern is 90 degrees counterclockwise.
3) As shown in FIG. 16, the first patterns LCP1 to LCP4, the second patterns UCP1 to UCP4, the count directions CD1, CD2, the complementary direction SD, and the complementary pattern corresponding to the specific patterns 1 to 4 of the vertical enlargement process SDP1 to SDP4 rotate these elements LCP1 to LCP4, UCP1 to UCP4, CD1, CD2, SD, and SDP1 to SDP4 in the horizontal enlargement process by 90 degrees (in the example of FIG. 16, 90 degrees counterclockwise). ).

  For example, the specific patterns 1 to 4 of the vertical enlargement process are respectively adjacent to the left of the central partial patterns MP1 to MP4 composed of three pixels arranged in the vertical direction and the central partial patterns MP1 to MP4. Partial patterns LP1 to LP4 and right partial patterns RP1 to RP4 adjacent in the right direction of the central partial pattern MP1 are included.

  The first patterns LCP1 to LCP4 of the vertical direction enlargement process are the same patterns as the partial patterns adjacent to the central pixel in the count direction CD1 among the three partial patterns included in the corresponding specific pattern. The second patterns UCP1 to UCP4 of the vertical expansion process are the same patterns as the partial patterns adjacent to the central pixel in the count direction CD2 among the three partial patterns included in the corresponding specific pattern.

Even when the vertical enlargement process is employed, the same operations and effects as the embodiment are obtained.
Further, as can be understood from the above description, one of the right direction and the left direction in the present modification is an example of the first direction, and one of the downward direction and the upward direction is the first direction. It is an example of the 2nd direction which crosses. Further, the left partial patterns LP1 and LP3 of the specific patterns 1 and 3 in the present modification are examples of the first partial pattern, and the right partial patterns RP1 and RP3 of the specific patterns 1 and 3 in the present modification are the second part. It is an example of a pattern. In addition, the right partial patterns RP2 and RP4 of the specific patterns 2 and 4 in this modification are examples of the first partial pattern, and the left partial patterns LP2 and LP4 of the specific patterns 2 and 4 in this modification are the second part. It is an example of a pattern.

(2) Instead of the horizontal enlargement processing (FIG. 9) in the above-described embodiment, the simple enlarged image is generated so that the simple enlarged image data representing the simple enlarged image is first generated and the complementary pixel is added to the simple enlarged image. The enlarged image data may be generated by correcting the data.

  FIG. 17 is a flowchart of the horizontal enlargement process in this modification. In step S602B, the enlargement processing unit M14 generates simple enlarged image data. In step S605, the enlargement processing unit M14 sequentially selects target pixels to be processed one by one from the pixels constituting the simple enlarged image. Specifically, the processing targets are processed downward in order from the top row of the simple enlarged image. In the same row, processing is sequentially performed from the leftmost pixel toward the right.

  In step S610B, as in step 610 of the embodiment, the enlargement processing unit M14 determines whether the target pixel is a white pixel. If it is determined that the target pixel is a white pixel (step S610B: YES), the pattern detection unit M142 of the enlargement processing unit M14 determines that the target pixel and its surrounding pixels are the following four types of identification in the simple enlarged image: It is determined whether or not any one of patterns 1 to 4 is formed (step S625B).

  FIG. 18 is a diagram for describing a specific pattern and a counting pattern in the horizontal enlargement process of the present modification. The specific patterns in this modification are specific patterns 1 to 4 (FIG. 18) of the enlarged image corresponding to the specific patterns 1 to 4 (FIG. 10) of the original image in the embodiment. The specific patterns 1 to 4 of the enlarged image in this modification are also referred to as corresponding specific patterns. For example, the correspondence specific patterns 1 to 4 are patterns of 3 vertical pixels × 4 horizontal pixels (12 pixels in total) including four vertical columns (FIG. 18). The middle two columns (second column and third column) of the corresponding specific patterns 1 to 4 are the central column of the three vertical columns constituting the specific patterns 1 to 4 (FIG. 10) of the original image. The same. The pattern detection unit M142 detects the corresponding specific patterns 1 to 4 of the enlarged image in the simple enlarged image, and thus is the same as the position on the enlarged image that is detected as the position where the complementary pixel is to be added in the embodiment. The position can be detected in a simple magnified image.

  When it is determined in step S610B that the target pixel is not a white pixel (step S610B: NO), and in step S625B, the target pixel and its surrounding pixels are four types of corresponding specific patterns 1 to 4 in the simple enlarged image. If it is determined that none of these are formed (step S625B: NO), the enlargement processing unit M14 advances the process to step S635.

  When it is determined that the target pixel and the surrounding pixels form any of the four types of correspondence specific patterns 1 to 4 in the simple enlarged image (step S625B: YES), the enlargement processing unit M14 performs the edge complement processing. Is executed (step S630B).

The processing flow of the edge complementation process of the present modification is basically the same as the edge complementation process (FIG. 11) in the embodiment, except for the following points.
1) In the present modification, the first continuous number CL and the second continuous number CU are counted in the simple enlarged image. In the present modification, the first patterns LCP1 to LCP4 and the second patterns UCP1 to UCP4 used for these counts are arranged in the horizontal direction as a part of the corresponding specific patterns 1 to 4, as shown in FIG. This is the same pattern as four pixels (any one of the upper part patterns UP1 to UP4 and the lower part patterns BP1 to BP4).

  In this way, even if the first continuous number CL and the second continuous number CU are counted in the simple enlarged image, the first continuous number CL and the second continuous number CU in the original image as in the embodiment. As a result, the first continuous number CL and the second continuous number CU have the same value. As a result, in any case, the continuous number determination unit M143 appropriately determines the complement number SC to a number corresponding to the first continuous number CL and the second continuous number CU in the original image. Can do.

  In the present modification, the first continuous number CL and the second continuous number CU may be counted in the original image as in the embodiment. However, if counting is performed in a simple enlarged image, the original image data may be deleted when the simple enlarged image data is generated, so that the amount of memory required for processing can be reduced.

  Even if the lateral enlargement process of this modification is employed, the same operations and effects as in the embodiment are obtained.

(3) In the horizontal enlargement process of the above embodiment, when the original image includes a specific pattern composed of white pixels and black pixels, black pixels are added to the enlarged image as complementary pixels. The combination is not limited to the combination of white pixels and black pixels, and may be a combination of a first type pixel and a second type pixel each representing a color having a relatively large difference in color (greater than a reference value). For example, among pixels representing gradation values of color components other than black (for example, any one of RGB and CMY), a combination of a pixel of a color near the maximum value and a pixel of a color near the minimum value Also good. The first type pixel has a specific gradation value (for example, any one of RGB gradation values, any one of CMYK gradation values) having a maximum value and a minimum value that the gradation value can take. It is preferable that one of the pixels is included, and the second type pixel includes a pixel in which the specific gradation value is the other of the maximum value and the minimum value that the gradation value can take. It is preferable.

(4) In the above embodiment, print data for monochrome printing is generated, but instead, print data for color printing may be generated. For example, a set of gradation values of color components (specifically, a set of gradation values of CMYK) corresponding to RGB image data or a printing material (specifically, CMYK toner) used for color printing. The above-described image processing may be performed on bitmap data (CMYK image data) composed of CMYK pixel data to be represented. Specifically, the printer driver M10 executes processing (FIG. 2: S600 to S900) including the above-described lateral enlargement processing for each single color image data represented by the pixel value of each color component. The compressed dot data 300 for each color component of CMYK may be generated. The printer driver M <b> 10 may generate print data using the compressed dot data 300 and transmit the print data to the printing apparatus 200.

(5) In the above embodiment, the counting pattern (the first pattern LCP and the second pattern UCP) is the same pattern as the partial specific pattern that is a part of the corresponding specific pattern. Different patterns may be used.

(6) In the above embodiment, after the dot image enlargement unit M18 generates uncompressed undistorted dot data, the compression unit M19 compresses the undistorted dot data and compresses the compressed dot data 300 (FIG. 5). ) Is generated. Alternatively, the dot image enlargement unit M18 may generate the compressed dot data 300 without using the distorted dot data to generate uncompressed undistorted dot data. Specifically, the dot image enlargement unit M18 compresses each row data included in the distorted dot data to generate the odd row data 310A, 320, 330 in the undistorted dot data, and the even row data 310B (ON May be added immediately after the odd-numbered row data. The dot image enlargement unit M18 repeats this process for all the row data included in the distorted dot data, thereby generating compressed undistorted dot data without generating uncompressed undistorted dot data. The dot data 300 may be generated. That is, the dot image enlargement unit M18 may generate undistorted dot data (compressed dot data 300) including compressed data representing a set of the same row using the distorted dot data.

(7) In the image processing of the above embodiment, the processing in steps S800 and S900 (FIG. 2) may be omitted, and the distorted dot data generated in S700 may be supplied to the printing apparatus 200 as print data. In this case, the apparatus control unit M20 of the printing apparatus 200 may generate undistorted dot data using the distorted dot data and supply the generated undistorted dot data to the printer engine 250. In this way, the printing apparatus 200 can print the undistorted dot image GD2 represented by the undistorted dot data, as in the above embodiment.

(8) The functional units M12 to M19 of the printer driver M10 in the above embodiment may be realized by the control circuit 212 of the printing apparatus 200. That is, the above-described image processing may be executed in the control circuit 212 of the printing apparatus 200. In this case, the appearance of the edge in the print image can be improved by the image processing in the printing apparatus 200.

(9) In each of the above embodiments, a part of the configuration realized by hardware may be replaced with software, and conversely, part or all of the configuration realized by software is replaced with hardware. You may do it.

  As mentioned above, although this invention was demonstrated based on the Example and the modification, Embodiment mentioned above is for making an understanding of this invention easy, and does not limit this invention. The present invention can be changed and improved without departing from the spirit and scope of the claims, and equivalents thereof are included in the present invention.

DESCRIPTION OF SYMBOLS 100 ... Calculation apparatus, 110 ... CPU, 120 ... Internal storage device, 130 ... External storage device, 132 ... Driver program, 134 ... Image data, 170 ... Operation unit, 180 ... display unit, 190 ... communication unit, 200 ... printing device, 210 ... integrated circuit, 212 ... control circuit, 214 ... volatile memory, 216 ... nonvolatile memory , 250 ... Printer engine, 270 ... Operation unit, 280 ... Display unit, 290 ... Communication unit, M10 ... Printer driver, M20 ... Device control unit, M12 ... Image data Acquisition unit, M14 ... enlargement processing unit, M16 ... halftone processing unit, M18 ... dot image enlargement unit, M19 ... compression unit, M141 ... target pixel selection unit, M142 ... pattern Detection unit, M143 ... continuous number determination unit, M144 ... pixel group selection unit, M145 ... pixel data setting unit

Claims (11)

An image processing apparatus,
An acquisition unit that acquires original image data representing an original image including the first type of pixels and the second type of pixels;
An enlargement processing unit that executes enlargement processing on the original image data and generates enlarged image data representing an enlarged image obtained by enlarging the original image in a first direction;
With
The enlargement processing unit
When the original image includes a specific pattern constituted by the first type pixel and the second type pixel, the original image extends in a second direction that intersects the first direction in the enlarged image. A pixel group selection unit that selects a pixel group, wherein the pixel group in the enlarged image is positioned in the second direction of the corresponding specific pixel corresponding to the specific pixel in the original image and the corresponding specific pixel The specific pixel in the original image is a pixel corresponding to the specific first type pixel that forms the specific pattern, and the pixel that forms the pixel group in the enlarged image Is a number according to the first continuous number and the second continuous number, and the first continuous number is a first number from the specific pixel toward the second direction in the original image. The number of continuous patterns, and the second continuous number is the original image Oite wherein Ri number der the second pattern is continuous from the specific pixel toward the opposite direction of the second direction, said first pattern, said one of the specific pattern, on the side of the second direction a part based pattern, said second pattern, said one of the specific pattern, wherein the Ru pattern der based on part of the opposite direction of the side, the pixel group selector in the second direction,
A setting unit that sets a pixel adjacent to the second type pixel in the first direction in the pixel group in the enlarged image as the second type pixel;
An image processing apparatus comprising: The image processing apparatus according to claim 1,
The first pattern includes a first central pixel that is the first type of pixel, and a first adjacent that is the first type of pixel that is adjacent to the first central pixel in the first direction. A pattern including a pixel and a second adjacent pixel that is the second type of pixel adjacent to the first central pixel in a direction opposite to the first direction;
The second pattern includes a second central pixel that is the second type pixel, and a third adjacent pixel that is the first type pixel adjacent to the second central pixel in the first direction. A pattern including pixels,
The position of the first central pixel in the first direction and the position of the second central pixel in the first direction are the position of the specific pixel in the original image in the first direction. An image processing apparatus that is the same. The image processing apparatus according to claim 1 or 2,
The first pattern is a first partial pattern that is a part of the specific pattern,
The image processing apparatus, wherein the second pattern is a second partial pattern that is a part of the specific pattern and is different from the first partial pattern. An image processing apparatus according to any one of claims 1 to 3,
The specific pattern includes a first partial pattern adjacent to the specific pixel in the second direction, and a second partial pattern adjacent to the specific pixel in a direction opposite to the second direction. ,
The first partial pattern is a central pixel that is adjacent to the specific pixel in the second direction, and a first periphery that is the first type of pixel that is adjacent to the central pixel in the first direction. A pattern including a pixel and a second peripheral pixel that is the second type of pixel adjacent to the central pixel in a direction opposite to the first direction,
The second partial pattern includes a third peripheral pixel that is the second type of pixel adjacent to the specific pixel in a direction opposite to the second direction, and the first peripheral pixel is the first peripheral pixel. An image processing apparatus, comprising: a fourth peripheral pixel that is the first type of pixel adjacent in the direction. An image processing apparatus according to any one of claims 1 to 4,
The enlargement processing unit
When the first continuous number is greater than the second continuous number, the number of pixels constituting the pixel group is determined using the second continuous number, and the first continuous number is An image processing apparatus comprising: a determination unit that determines the number of pixels constituting the pixel group using the first continuous number when the number is smaller than the second continuous number. An image processing apparatus according to any one of claims 1 to 5,
The enlargement processing unit includes a target pixel selection unit that sequentially selects a target pixel from among a plurality of pixels constituting the original image,
The enlargement processing unit generates the enlarged image data by executing one of a plurality of processes including a first process and a second process each time the target pixel is selected,
The first process is a process that is executed when the target pixel includes the specific pixel, and the selection of the pixel group by the pixel group selection unit and the setting of the pixel group that constitutes the pixel group by the setting unit. And processing including setting,
The second process is a process that is executed when the target pixel does not include the specific pixel, and the pixel group selection unit by the pixel group selection unit and the pixels that configure the pixel group by the setting unit The image processing apparatus is a process that does not include the setting. An image processing apparatus according to any one of claims 1 to 6,
The enlargement processing unit performs the enlargement process on the original image without distortion, and generates the enlarged image data representing the enlarged image with distortion,
The image processing apparatus is an apparatus for a print execution unit that prints a dot image;
The image processing apparatus further includes:
A halftone process for generating dot data representing a dot formation state for each pixel is performed on the enlarged image data representing the enlarged image with distortion generated by the enlargement processing unit, and distortion with distortion is performed. A halftone processing unit for generating distorted dot data representing a dot image;
Dots that perform processing different from the enlargement processing on the distorted dot data to generate undistorted dot data representing an undistorted dot image in which the distorted dot image is expanded at least in the second direction. An image magnifier,
An image processing apparatus comprising: The image processing apparatus according to claim 7,
The undistorted dot image includes a plurality of sets of the same row,
The set of the same row is adjacent to each other among a plurality of rows along the first direction constituting the undistorted dot image, and two or more dot formation states of the constituent pixels are the same. A set containing lines,
The undistorted dot data includes compressed data representing the set of the same row,
The compressed data includes an image processing apparatus including representative row data representing one representative row and data indicating that the representative row data is repeated. An image processing apparatus according to any one of claims 1 to 8,
The enlargement processing unit includes a detection unit that detects the specific pattern in the original image,
The enlargement processing unit is configured to perform selection of the pixel group by the pixel group selection unit and setting of pixels constituting the pixel group by the setting unit with respect to the detected specific pattern. An image processing apparatus according to any one of claims 1 to 8,
The enlargement processing unit includes a detection unit that detects a corresponding specific pattern corresponding to the specific pattern of the original image in the enlarged image,
The enlargement processing unit executes selection of the pixel group by the pixel group selection unit and setting of pixels constituting the pixel group by the setting unit for the detected correspondence specific pattern. . An image processing program,
An acquisition function for acquiring original image data representing an original image including a first type pixel and a second type pixel;
An enlargement processing function for executing enlargement processing on the original image data and generating enlarged image data representing an enlarged image obtained by enlarging the original image in a first direction;
Is realized on a computer,
The enlargement processing function is:
When the original image includes a specific pattern constituted by the first type pixel and the second type pixel, the original image extends in a second direction that intersects the first direction in the enlarged image. A pixel group selection function for selecting a pixel group, wherein the pixel group in the enlarged image is positioned in the second direction of the corresponding specific pixel corresponding to the specific pixel in the original image and the corresponding specific pixel The specific pixel in the original image is a pixel corresponding to the specific first type pixel that forms the specific pattern, and the pixel that forms the pixel group in the enlarged image Is a number according to the first continuous number and the second continuous number, and the first continuous number is a first number from the specific pixel toward the second direction in the original image. The number of consecutive patterns, and the second consecutive number is the original image Ri number der the second pattern is continuous toward the opposite direction of the second direction from the specified pixel in the first pattern, of the specific pattern, on the side of the second direction one- a pattern based on parts, the second pattern, of the specific pattern, the Ru pattern der based on a part of the opposite direction of the side of the second direction, and the pixel group selection function,
A setting function for setting a pixel adjacent to the second type pixel in the first direction in the pixel group in the enlarged image as the second type pixel;
An image processing program.

Images